(1) Field of the Invention
The present invention relates to a robot route interpolation method for interpolating a polygonal route of a robot which is defined by the predetermined three or more points.
(2) Description of the Prior Art
As shown in FIG. 3, when a robot hand (not shown) is moved along a polygonal route 1 which is defined by the predetermined three points A, B and C, the route becomes discontinuous at the turning point B and therefore, a velocity change or an acceleration also becomes discontinuous.
As a result, there is arisen such a drawback as exerting a greater shock on the above robot hand.
Accordingly, in order to solve the above drawback, there has been proposed a route interpolation method in which the above polygonal route 1 is interpolated by a curve line so as not to pass the above turning point B.
For example, in the technical teaching disclosed in Japanese Patent Publication No. hei 1-27443, an interpolation is carried out in the following manners. First, along a route of a straight line before a turning point, the robot hand is moved toward a turning point at a velocity which is monotonously reduced and becomes zero at the turning point. Next, along a route of a straight line after the turning point, the robot hand is moved at a velocity which is monotonously increased from zero to the predetermined velocity. Then, there is added an increment from the above turning point to the position determined by the above velocity increasing interpolation, on the position determined by the above velocity reducing interpolation, to thereby form the route.
However, in the above prior art, the route interpolation is carried out by adding vectors which are changed in uniformly reduced velocity or uniform acceleration, so that the acceleration becomes larger as an angle formed between two adjacent lines of the polygonal route (refer to FIG. 3) becomes small, thus exerting a greater shock on the robot hand.